Static random access memory (SRAM) is memory that utilizes latching to store each bit. Because SRAM is static, there is no need to periodically refresh the memory, and is, therefore, typically faster, less dense, and more expensive, than dynamic random-access memory (DRAM). Due to SRAM's speed, SRAM is typically used in computer applications that require a fast memory such as cache memory for the central processing unit (CPU), external burst mode SRAM caches, hard disk buffers, router buffers, CPU register files, etc. While SRAM is fast, it also consumes a significant portion of system's level dynamic power. In some cases SRAM may consume as much as 90% of the system level dynamic power.